The present invention is directed to a scanning apparatus and in particular to a high-speed scanning apparatus for detecting objects or events on a moving target such as a web for the purpose of detecting changes or faults therein.
Scanning apparatus are known in the prior art, for example as disclosed in U.S. Pat. No. 4,265,545. The disadvantage of that and other prior art systems, is that in order to accommodate wide moving webs having widths of up to 60" and traveling at speeds of up to 1200 feet per minute, scanners, and in particular inspection systems, need complex and costly optical elements in order to detect flaws at a sufficient level of resolution.